Coordinated changes in mRNA turnover, translation, and RNA processing bodies in bronchial epithelial cells following inflammatory stimulation.
Bronchial epithelial cells play a pivotal role in airway inflammation, but little is known about posttranscriptional regulation of mediator gene expression during the inflammatory response in these cells. Here, we show that activation of human bronchial epithelial BEAS-2B cells by proinflammatory cytokines interleukin-4 (IL-4) and tumor necrosis factor alpha (TNF-alpha) leads to an increase in the mRNA stability of the key chemokines monocyte chemotactic protein 1 and IL-8, an elevation of the global translation rate, an increase in the levels of several proteins critical for translation, and a reduction of microRNA-mediated translational repression. Moreover, using the BEAS-2B cell system and a mouse model, we found that RNA processing bodies (P bodies), cytoplasmic domains linked to storage and/or degradation of translationally silenced mRNAs, are significantly reduced in activated bronchial epithelial cells, suggesting a physiological role for P bodies in airway inflammation. Our study reveals an orchestrated change among posttranscriptional mechanisms, which help sustain high levels of inflammatory mediator production in bronchial epithelium during the pathogenesis of inflammatory airway diseases.
Zhai
Yuxin
Y
Department of Biochemistry and Molecular Biology, The University of Texas-Houston Medical School, Houston, TX 77030, USA.
Zhong
Zhenping
Z
Chen
Chyi-Ying A
CY
Xia
Zhenfang
Z
Song
Ling
L
Blackburn
Michael R
MR
Shyu
Ann-Bin
AB
D000818:Animals; D001980:Bronchi / Q000166:cytology*; D002460:Cell Line; D018932:Chemokine CCL2 / Q000235:genetics / Q000378:metabolism; D004847:Epithelial Cells / Q000166:cytology / Q000502:physiology*; D005786:Gene Expression Regulation; D006801:Humans; D007249:Inflammation / Q000276:immunology*; D015847:Interleukin-4 / Q000235:genetics / Q000378:metabolism; D016209:Interleukin-8 / Q000235:genetics / Q000378:metabolism; D051379:Mice; D035683:MicroRNAs / Q000235:genetics / Q000378:metabolism; D014176:Protein Biosynthesis / Q000502:physiology*; D020871:RNA Stability; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism*; D012335:RNA, Ribosomal / Q000235:genetics / Q000378:metabolism; D014409:Tumor Necrosis Factor-alpha / Q000235:genetics / Q000378:metabolism
D018932:Chemokine CCL2; D016209:Interleukin-8; D035683:MicroRNAs; D012333:RNA, Messenger; D012335:RNA, Ribosomal; D014409:Tumor Necrosis Factor-alpha; D015847:Interleukin-4